1. Field of the Invention
The invention relates to a circuit arrangement comprising a tuner and a splitter-modulator comprising a splitter and a modulator, in which the splitter has an RF signal input for applying an RF input signal, an RF signal output for supplying an RF output signal, a first line for applying the RF input signal to the tuner and a second line for supplying an RF output signal from the modulator, the tuner being adapted to demodulate the RF input signal and the modulator being adapted to convert a baseband signal into the RF output signal to be supplied by said modulator, and comprising devices for generating reference oscillations for the tuner and the splitter-modulator, said devices having at least one quartz crystal which is common for the tuner and the splitter-modulator, and a phase-locked loop which is common for the tuner and the splitter-modulator.
2. Description of the Related Art
Such a circuit arrangement is described in European Patent Application 95 200 961.1, corresponding to U.S. Pat. No. 5,640,688. The object of this circuit arrangement described in said application is the use of a small number of components for a circuit arrangement comprising both a tuner and a splitter-modulator. An arrangement having a particularly small number of components uses a sole oscillation generator with a single oscillator stage, both for the modulator in the splitter and for the tuner.
For tuning the tuner to different transmitters, a synchronization of the adjustment of filter stages in the tuner and the adjustment of the oscillator stage is required, which necessitates the use of a large number of components in the dimensioning of the tuning element of the filter stages and the oscillator stage when strict requirements are imposed on the signal-processing quality.